Others burned small patches of brush or were lit but failed to catch on. The only property damage since the fires began Saturday has been to a yard fence and a utility pole that were near a Dumpster set ablaze.

Fire crews have jumped from one incident to the next, working overnight the last several days. As of Tuesday morning, officials had not identified a suspect and were planning to offer a reward for information leading to an arrest, the newspaper reported.

"As far as a cause, we don't have any obvious signs of what's being used to ignite these fires," a Novato police captain told the Independent Journal.